Automotive
New Car Fuel Calculator
Calculate city and highway mileage, annual gallons, distance-weighted combined MPG, current annual fuel cost, cost per mile, cumulative horizon cost, and annual tailpipe emissions. The dedicated route-and-fuel visual connects driving mix to gallons, cost, and emissions.
Annual city miles-
Annual highway miles-
Annual fuel volume (gallons)-
Distance-weighted combined economy (mpg)-
Current annual fuel cost-
Current fuel cost per mile-
Cumulative fuel cost through horizon-
Annual tailpipe emissions (kg CO2e)-
Decision view
City-highway fuel and ownership path
City-highway fuel and ownership pathCity and highway miles are converted to gallons before cost, combined MPG, and entered-factor emissions are derived.
Exact scenario comparisonCurrent fuel price per gallon changes while all other entered assumptions remain constant.
| Current fuel price per gallon | Annual city miles | Annual highway miles | Annual fuel volume (gallons) | Distance-weighted combined economy (mpg) | Current annual fuel cost | Current fuel cost per mile | Cumulative fuel cost through horizon | Annual tailpipe emissions (kg CO2e) |
|---|
Fuel detail
Annual cost schedule and driving-segment reconciliation
How to use New Car Fuel Calculator
- Enter representative annual mileage and a city share that sums with highway travel to 100%.
- Use observed or defensible city and highway MPG in US miles per gallon.
- Stress-test fuel price, mileage, and efficiency rather than treating one scenario as a forecast.
Calculator guide
Understanding New Car Fuel Calculator
Combined fuel economy should be derived from gallons consumed, not by directly averaging city and highway MPG. This calculator splits annual mileage, calculates fuel for each segment, and then builds cost, multi-year price growth, and entered-factor tailpipe emissions.
Calculation method
How the calculation works
Split annual distance into city and highway segments, calculate fuel use from each segment's efficiency, and compound only the entered fuel-price assumption across the ownership horizon. Allocate miles by city share, divide each segment by its own MPG, sum gallons, derive combined MPG from total miles divided by gallons, and compound only fuel price across the entered ownership horizon.
Ownership check
Use the fuel result inside a complete vehicle budget
Fuel is important, but it is only one ownership-cost layer.
Worked situations
Practical examples
- City and highway MPG are converted to gallons before they are combined.
- A larger city share raises fuel use when city MPG is lower.
- Fuel-price growth changes cost through the horizon but does not change gallons.
Better inputs
Useful tips
- Use fill-to-fill records when the vehicle is already in service.
- Separate towing, winter, idling, or commercial duty when those patterns are material.
- Compare cost per mile with maintenance, insurance, depreciation, and financing separately.
Before relying on the result
Limitations and common mistakes
- Annual mileage, city share, and fuel economy remain constant across the horizon.
- Traffic, weather, load, idling, maintenance, tire pressure, driving style, and fuel blend are not predicted.
- Tailpipe factor excludes upstream fuel production and vehicle manufacturing.
Reference
Key terms
- Combined MPG
- Total miles divided by total city-plus-highway gallons.
- City share
- Entered percentage of annual miles driven under city conditions.
- Cost per mile
- Current annual fuel spending divided by annual miles.
- Tailpipe factor
- Entered kilograms CO2e per gallon consumed.
Important note
Calculated from the entered vehicle and operating values. Actual prices, financing terms, efficiency, maintenance, insurance, taxes, and resale outcomes can differ.
Frequently asked questions
Why not average city and highway MPG?
MPG is a rate; gallons must be calculated for each distance segment before deriving a combined rate.
Does inflation change fuel use?
No. It changes modeled fuel price only.
Are emissions lifecycle emissions?
No. They use the entered tailpipe factor per gallon.
Can this compare two cars?
Run each vehicle with the same distance, city share, price, and horizon assumptions.